src/journal-remote/journal-remote.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <stdlib.h>
   6 #include <sys/prctl.h>
   7 #include <stdint.h>
   8
   9 #include "sd-daemon.h"
  10
  11 #include "alloc-util.h"
  12 #include "def.h"
  13 #include "errno-util.h"
  14 #include "escape.h"
  15 #include "fd-util.h"
  16 #include "journal-file.h"
  17 #include "journal-remote-write.h"
  18 #include "journal-remote.h"
  19 #include "journald-native.h"
  20 #include "macro.h"
  21 #include "parse-util.h"
  22 #include "process-util.h"
  23 #include "socket-util.h"
  24 #include "stdio-util.h"
  25 #include "string-util.h"
  26 #include "strv.h"
  27
  28 #define REMOTE_JOURNAL_PATH "/var/log/journal/remote"
  29
  30 #define filename_escape(s) xescape((s), "/ ")
  31
  32 static int open_output(RemoteServer *s, Writer *w, const char* host) {
  33         _cleanup_free_ char *_filename = NULL;
  34         const char *filename;
  35         int r;
  36
  37         switch (s->split_mode) {
  38         case JOURNAL_WRITE_SPLIT_NONE:
  39                 filename = s->output;
  40                 break;
  41
  42         case JOURNAL_WRITE_SPLIT_HOST: {
  43                 _cleanup_free_ char *name;
  44
  45                 assert(host);
  46
  47                 name = filename_escape(host);
  48                 if (!name)
  49                         return log_oom();
  50
  51                 r = asprintf(&_filename, "%s/remote-%s.journal", s->output, name);
  52                 if (r < 0)
  53                         return log_oom();
  54
  55                 filename = _filename;
  56                 break;
  57         }
  58
  59         default:
  60                 assert_not_reached("what?");
  61         }
  62
  63         r = journal_file_open_reliably(filename,
  64                                        O_RDWR|O_CREAT, 0640,
  65                                        s->compress, (uint64_t) -1, s->seal,
  66                                        &w->metrics,
  67                                        w->mmap, NULL,
  68                                        NULL, &w->journal);
  69         if (r < 0)
  70                 return log_error_errno(r, "Failed to open output journal %s: %m", filename);
  71
  72         log_debug("Opened output file %s", w->journal->path);
  73         return 0;
  74 }
  75
  76 /**********************************************************************
  77  **********************************************************************
  78  **********************************************************************/
  79
  80 static int init_writer_hashmap(RemoteServer *s) {
  81         static const struct hash_ops* const hash_ops[] = {
  82                 [JOURNAL_WRITE_SPLIT_NONE] = NULL,
  83                 [JOURNAL_WRITE_SPLIT_HOST] = &string_hash_ops,
  84         };
  85
  86         assert(s);
  87         assert(s->split_mode >= 0 && s->split_mode < (int) ELEMENTSOF(hash_ops));
  88
  89         s->writers = hashmap_new(hash_ops[s->split_mode]);
  90         if (!s->writers)
  91                 return log_oom();
  92
  93         return 0;
  94 }
  95
  96 int journal_remote_get_writer(RemoteServer *s, const char *host, Writer **writer) {
  97         _cleanup_(writer_unrefp) Writer *w = NULL;
  98         const void *key;
  99         int r;
 100
 101         switch(s->split_mode) {
 102         case JOURNAL_WRITE_SPLIT_NONE:
 103                 key = "one and only";
 104                 break;
 105
 106         case JOURNAL_WRITE_SPLIT_HOST:
 107                 assert(host);
 108                 key = host;
 109                 break;
 110
 111         default:
 112                 assert_not_reached("what split mode?");
 113         }
 114
 115         w = hashmap_get(s->writers, key);
 116         if (w)
 117                 writer_ref(w);
 118         else {
 119                 w = writer_new(s);
 120                 if (!w)
 121                         return log_oom();
 122
 123                 if (s->split_mode == JOURNAL_WRITE_SPLIT_HOST) {
 124                         w->hashmap_key = strdup(key);
 125                         if (!w->hashmap_key)
 126                                 return log_oom();
 127                 }
 128
 129                 r = open_output(s, w, host);
 130                 if (r < 0)
 131                         return r;
 132
 133                 r = hashmap_put(s->writers, w->hashmap_key ?: key, w);
 134                 if (r < 0)
 135                         return r;
 136         }
 137
 138         *writer = TAKE_PTR(w);
 139
 140         return 0;
 141 }
 142
 143 /**********************************************************************
 144  **********************************************************************
 145  **********************************************************************/
 146
 147 /* This should go away as soon as µhttpd allows state to be passed around. */
 148 RemoteServer *journal_remote_server_global;
 149
 150 static int dispatch_raw_source_event(sd_event_source *event,
 151                                      int fd,
 152                                      uint32_t revents,
 153                                      void *userdata);
 154 static int dispatch_raw_source_until_block(sd_event_source *event,
 155                                            void *userdata);
 156 static int dispatch_blocking_source_event(sd_event_source *event,
 157                                           void *userdata);
 158 static int dispatch_raw_connection_event(sd_event_source *event,
 159                                          int fd,
 160                                          uint32_t revents,
 161                                          void *userdata);
 162
 163 static int get_source_for_fd(RemoteServer *s,
 164                              int fd, char *name, RemoteSource **source) {
 165         Writer *writer;
 166         int r;
 167
 168         /* This takes ownership of name, but only on success. */
 169
 170         assert(fd >= 0);
 171         assert(source);
 172
 173         if (!GREEDY_REALLOC0(s->sources, s->sources_size, fd + 1))
 174                 return log_oom();
 175
 176         r = journal_remote_get_writer(s, name, &writer);
 177         if (r < 0)
 178                 return log_warning_errno(r, "Failed to get writer for source %s: %m",
 179                                          name);
 180
 181         if (!s->sources[fd]) {
 182                 s->sources[fd] = source_new(fd, false, name, writer);
 183                 if (!s->sources[fd]) {
 184                         writer_unref(writer);
 185                         return log_oom();
 186                 }
 187
 188                 s->active++;
 189         }
 190
 191         *source = s->sources[fd];
 192         return 0;
 193 }
 194
 195 static int remove_source(RemoteServer *s, int fd) {
 196         RemoteSource *source;
 197
 198         assert(s);
 199         assert(fd >= 0 && fd < (ssize_t) s->sources_size);
 200
 201         source = s->sources[fd];
 202         if (source) {
 203                 /* this closes fd too */
 204                 source_free(source);
 205                 s->sources[fd] = NULL;
 206                 s->active--;
 207         }
 208
 209         return 0;
 210 }
 211
 212 int journal_remote_add_source(RemoteServer *s, int fd, char* name, bool own_name) {
 213         RemoteSource *source = NULL;
 214         int r;
 215
 216         /* This takes ownership of name, even on failure, if own_name is true. */
 217
 218         assert(s);
 219         assert(fd >= 0);
 220         assert(name);
 221
 222         if (!own_name) {
 223                 name = strdup(name);
 224                 if (!name)
 225                         return log_oom();
 226         }
 227
 228         r = get_source_for_fd(s, fd, name, &source);
 229         if (r < 0) {
 230                 log_error_errno(r, "Failed to create source for fd:%d (%s): %m",
 231                                 fd, name);
 232                 free(name);
 233                 return r;
 234         }
 235
 236         r = sd_event_add_io(s->events, &source->event,
 237                             fd, EPOLLIN|EPOLLRDHUP|EPOLLPRI,
 238                             dispatch_raw_source_event, source);
 239         if (r == 0) {
 240                 /* Add additional source for buffer processing. It will be
 241                  * enabled later. */
 242                 r = sd_event_add_defer(s->events, &source->buffer_event,
 243                                        dispatch_raw_source_until_block, source);
 244                 if (r == 0)
 245                         sd_event_source_set_enabled(source->buffer_event, SD_EVENT_OFF);
 246         } else if (r == -EPERM) {
 247                 log_debug("Falling back to sd_event_add_defer for fd:%d (%s)", fd, name);
 248                 r = sd_event_add_defer(s->events, &source->event,
 249                                        dispatch_blocking_source_event, source);
 250                 if (r == 0)
 251                         sd_event_source_set_enabled(source->event, SD_EVENT_ON);
 252         }
 253         if (r < 0) {
 254                 log_error_errno(r, "Failed to register event source for fd:%d: %m",
 255                                 fd);
 256                 goto error;
 257         }
 258
 259         r = sd_event_source_set_description(source->event, name);
 260         if (r < 0) {
 261                 log_error_errno(r, "Failed to set source name for fd:%d: %m", fd);
 262                 goto error;
 263         }
 264
 265         return 1; /* work to do */
 266
 267  error:
 268         remove_source(s, fd);
 269         return r;
 270 }
 271
 272 int journal_remote_add_raw_socket(RemoteServer *s, int fd) {
 273         int r;
 274         _cleanup_close_ int fd_ = fd;
 275         char name[STRLEN("raw-socket-") + DECIMAL_STR_MAX(int) + 1];
 276
 277         assert(fd >= 0);
 278
 279         r = sd_event_add_io(s->events, &s->listen_event,
 280                             fd, EPOLLIN,
 281                             dispatch_raw_connection_event, s);
 282         if (r < 0)
 283                 return r;
 284
 285         xsprintf(name, "raw-socket-%d", fd);
 286
 287         r = sd_event_source_set_description(s->listen_event, name);
 288         if (r < 0)
 289                 return r;
 290
 291         fd_ = -1;
 292         s->active++;
 293         return 0;
 294 }
 295
 296 /**********************************************************************
 297  **********************************************************************
 298  **********************************************************************/
 299
 300 int journal_remote_server_init(
 301                 RemoteServer *s,
 302                 const char *output,
 303                 JournalWriteSplitMode split_mode,
 304                 bool compress,
 305                 bool seal) {
 306
 307         int r;
 308
 309         assert(s);
 310
 311         assert(journal_remote_server_global == NULL);
 312         journal_remote_server_global = s;
 313
 314         s->split_mode = split_mode;
 315         s->compress = compress;
 316         s->seal = seal;
 317
 318         if (output)
 319                 s->output = output;
 320         else if (split_mode == JOURNAL_WRITE_SPLIT_NONE)
 321                 s->output = REMOTE_JOURNAL_PATH "/remote.journal";
 322         else if (split_mode == JOURNAL_WRITE_SPLIT_HOST)
 323                 s->output = REMOTE_JOURNAL_PATH;
 324         else
 325                 assert_not_reached("bad split mode");
 326
 327         r = sd_event_default(&s->events);
 328         if (r < 0)
 329                 return log_error_errno(r, "Failed to allocate event loop: %m");
 330
 331         r = init_writer_hashmap(s);
 332         if (r < 0)
 333                 return r;
 334
 335         return 0;
 336 }
 337
 338 #if HAVE_MICROHTTPD
 339 static void MHDDaemonWrapper_free(MHDDaemonWrapper *d) {
 340         MHD_stop_daemon(d->daemon);
 341         sd_event_source_unref(d->io_event);
 342         sd_event_source_unref(d->timer_event);
 343         free(d);
 344 }
 345 #endif
 346
 347 void journal_remote_server_destroy(RemoteServer *s) {
 348         size_t i;
 349
 350 #if HAVE_MICROHTTPD
 351         hashmap_free_with_destructor(s->daemons, MHDDaemonWrapper_free);
 352 #endif
 353
 354         assert(s->sources_size == 0 || s->sources);
 355         for (i = 0; i < s->sources_size; i++)
 356                 remove_source(s, i);
 357         free(s->sources);
 358
 359         writer_unref(s->_single_writer);
 360         hashmap_free(s->writers);
 361
 362         sd_event_source_unref(s->sigterm_event);
 363         sd_event_source_unref(s->sigint_event);
 364         sd_event_source_unref(s->listen_event);
 365         sd_event_unref(s->events);
 366
 367         if (s == journal_remote_server_global)
 368                 journal_remote_server_global = NULL;
 369
 370         /* fds that we're listening on remain open... */
 371 }
 372
 373 /**********************************************************************
 374  **********************************************************************
 375  **********************************************************************/
 376
 377 int journal_remote_handle_raw_source(
 378                 sd_event_source *event,
 379                 int fd,
 380                 uint32_t revents,
 381                 RemoteServer *s) {
 382
 383         RemoteSource *source;
 384         int r;
 385
 386         /* Returns 1 if there might be more data pending,
 387          * 0 if data is currently exhausted, negative on error.
 388          */
 389
 390         assert(fd >= 0 && fd < (ssize_t) s->sources_size);
 391         source = s->sources[fd];
 392         assert(source->importer.fd == fd);
 393
 394         r = process_source(source, s->compress, s->seal);
 395         if (journal_importer_eof(&source->importer)) {
 396                 size_t remaining;
 397
 398                 log_debug("EOF reached with source %s (fd=%d)",
 399                           source->importer.name, source->importer.fd);
 400
 401                 remaining = journal_importer_bytes_remaining(&source->importer);
 402                 if (remaining > 0)
 403                         log_notice("Premature EOF. %zu bytes lost.", remaining);
 404                 remove_source(s, source->importer.fd);
 405                 log_debug("%zu active sources remaining", s->active);
 406                 return 0;
 407         } else if (r == -E2BIG) {
 408                 log_notice("Entry with too many fields, skipped");
 409                 return 1;
 410         } else if (r == -ENOBUFS) {
 411                 log_notice("Entry too big, skipped");
 412                 return 1;
 413         } else if (r == -EAGAIN) {
 414                 return 0;
 415         } else if (r < 0) {
 416                 log_debug_errno(r, "Closing connection: %m");
 417                 remove_source(s, fd);
 418                 return 0;
 419         } else
 420                 return 1;
 421 }
 422
 423 static int dispatch_raw_source_until_block(sd_event_source *event,
 424                                            void *userdata) {
 425         RemoteSource *source = userdata;
 426         int r;
 427
 428         /* Make sure event stays around even if source is destroyed */
 429         sd_event_source_ref(event);
 430
 431         r = journal_remote_handle_raw_source(event, source->importer.fd, EPOLLIN, journal_remote_server_global);
 432         if (r != 1)
 433                 /* No more data for now */
 434                 sd_event_source_set_enabled(event, SD_EVENT_OFF);
 435
 436         sd_event_source_unref(event);
 437
 438         return r;
 439 }
 440
 441 static int dispatch_raw_source_event(sd_event_source *event,
 442                                      int fd,
 443                                      uint32_t revents,
 444                                      void *userdata) {
 445         RemoteSource *source = userdata;
 446         int r;
 447
 448         assert(source->event);
 449         assert(source->buffer_event);
 450
 451         r = journal_remote_handle_raw_source(event, fd, EPOLLIN, journal_remote_server_global);
 452         if (r == 1)
 453                 /* Might have more data. We need to rerun the handler
 454                  * until we are sure the buffer is exhausted. */
 455                 sd_event_source_set_enabled(source->buffer_event, SD_EVENT_ON);
 456
 457         return r;
 458 }
 459
 460 static int dispatch_blocking_source_event(sd_event_source *event,
 461                                           void *userdata) {
 462         RemoteSource *source = userdata;
 463
 464         return journal_remote_handle_raw_source(event, source->importer.fd, EPOLLIN, journal_remote_server_global);
 465 }
 466
 467 static int accept_connection(
 468                 const char* type,
 469                 int fd,
 470                 SocketAddress *addr,
 471                 char **hostname) {
 472
 473         _cleanup_close_ int fd2 = -1;
 474         int r;
 475
 476         log_debug("Accepting new %s connection on fd:%d", type, fd);
 477         fd2 = accept4(fd, &addr->sockaddr.sa, &addr->size, SOCK_NONBLOCK|SOCK_CLOEXEC);
 478         if (fd2 < 0) {
 479                 if (ERRNO_IS_ACCEPT_AGAIN(errno))
 480                         return -EAGAIN;
 481
 482                 return log_error_errno(errno, "accept() on fd:%d failed: %m", fd);
 483         }
 484
 485         switch(socket_address_family(addr)) {
 486         case AF_INET:
 487         case AF_INET6: {
 488                 _cleanup_free_ char *a = NULL;
 489                 char *b;
 490
 491                 r = socket_address_print(addr, &a);
 492                 if (r < 0)
 493                         return log_error_errno(r, "socket_address_print(): %m");
 494
 495                 r = socknameinfo_pretty(&addr->sockaddr, addr->size, &b);
 496                 if (r < 0)
 497                         return log_error_errno(r, "Resolving hostname failed: %m");
 498
 499                 log_debug("Accepted %s %s connection from %s",
 500                           type,
 501                           socket_address_family(addr) == AF_INET ? "IP" : "IPv6",
 502                           a);
 503
 504                 *hostname = b;
 505                 return TAKE_FD(fd2);
 506         }
 507
 508         default:
 509                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 510                                        "Rejected %s connection with unsupported family %d",
 511                                        type, socket_address_family(addr));
 512         }
 513 }
 514
 515 static int dispatch_raw_connection_event(
 516                 sd_event_source *event,
 517                 int fd,
 518                 uint32_t revents,
 519                 void *userdata) {
 520
 521         RemoteServer *s = userdata;
 522         int fd2;
 523         SocketAddress addr = {
 524                 .size = sizeof(union sockaddr_union),
 525                 .type = SOCK_STREAM,
 526         };
 527         char *hostname = NULL;
 528
 529         fd2 = accept_connection("raw", fd, &addr, &hostname);
 530         if (fd2 == -EAGAIN)
 531                 return 0;
 532         if (fd2 < 0)
 533                 return fd2;
 534
 535         return journal_remote_add_source(s, fd2, hostname, true);
 536 }